Troubleshooting - BRAND HF Mode D'emploi

Troubleshooting

Problem
Piston is diffi cult to move
Filling not possible
Instrument does not
dispense liquid
Air bubbles in the instrument
Dispensed volume is too low
Possible cause
- Formation of crystals, dirty
- Volume adjusted to minimum setting
- Sticking fi lling valve
- Sticking discharge valve
- Reagent with high vapor pressure has been
drawn in too quickly
- Seal not inserted, knurled locking nuts not fi rmly
connected
- Air not expelled from the instrument
- Filling tube not fi rmly connected or damaged
- Valves dirty, not fi rmly installed or damaged
- Backfl ow tube not connected
- Discharge tube not fi rmly connected or damaged
- Filling tube not fi rmly connected or damaged
- Valves not fi rmly connected or damaged
Corrective action
- Stop dispensing immediately. Loose piston by circular motion,
but do not disassemble. Follow all cleaning instructions
(➤ page 16).
- Set to required volume (➤ page 12).
- Clean fi lling valve (➤ page 18). If necessary replace the valve
with sealing washer.
- Clean discharge valve. If valve ball is stuck use yellow plastic
pipette tip (100 µl) to loosen it. If necessary replace discharge
valve.
- Slowly draw in reagent.
- Double check that seal (K) is in place, and that the knurled
locking nuts at the discharge tube and the SafetyPrime
are fi rmly seated and fi nger tight.
- Remove air (➤ page 11).
- Push the fi lling tube on fi rmly. If necessary cut off approx.
1 cm of tube at the upper end and re-connect it or replace
fi lling tube.
- Cleaning procedure (➤ page 16). Tighten the valves using
the mounting tool. If necessary, replace the valves and sealing
washers.
- Connect backfl ow tube (➤ page 10, N).
- Push the original manufacturer's discharge tube on fi rmly.
Replace a deformed or damaged discharge tube.
- Cleaning procedure (➤ page 16. Push the fi lling tube on fi rmly.
If this does not suffi ce, cut off approx. 1 cm of the tube at the
upper end and re-connect it or replace fi lling tube
(➤ page 30).
- Cleaning procedure (➤ page 16). Tighten the valves using
the mounting tool. If necessary, replace valves and sealing
washers.
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™
valve